This is just a question if anyone knows if this works or doesn't. I'm being asked by a tech that wants to install our product. Clients are on one domain but the server is in a different domain but both domains are using the same IP range? Haven't ever been asked this one before and I don't have a way to setup that type of environment. Thanks.

FWIW: This is really a network routing question and not really a question about domains. (I.e. this is not a question about SQL Anywhere).

If you have two different subnets that have the same IP range then you need to figure out how to route packets from one subnet to the other. There is undoubtly some network switch or router that is between the two networks. You will need to use NAT on at least one of the network switches/routers so that on one network the other network "appears" to be using a different IP range.

Just a hint: in a huge network even if all computers are in the same subnet the switches tend to be configured in a way, that broadcasts are not distributed to all computers. So you might have to tell your SQLA client on which ip specifically to look for the server. Check Host connection parameter for details.